Adjust completenames tests for cmd2 0.7.3+

cmd2 0.7.3 started to override Cmd.completenames with a function
taking additional parameters:

  Cmd2.completenames(self, text, line, begidx, endidx)

over the Cmd version:

  Cmd.completenames(self, text, *ignored)

With this change we adjust the override to the new signature.

Change-Id: I7b110502c20ec16c6032cce31021eee3f85255fc
Closes-Bug: #1700250

cliff/interactive.py

@@ -60,13 +60,13 @@ class InteractiveApp(cmd2.Cmd):
         line_parts = shlex.split(line.parsed.raw)
         self.parent_app.run_subcommand(line_parts)
 
-    def completenames(self, text, *ignored):
+    def completenames(self, text, line, begidx, endidx):
         """Tab-completion for command prefix without completer delimiter.
 
         This method returns cmd style and cliff style commands matching
         provided command prefix (text).
         """
-        completions = cmd2.Cmd.completenames(self, text, *ignored)
+        completions = cmd2.Cmd.completenames(self, text, line, begidx, endidx)
         completions += self._complete_prefix(text)
         return completions
 

cliff/tests/test_interactive.py

@@ -31,7 +31,8 @@ class TestInteractive(base.TestBase):
 
     def _test_completenames(self, expecteds, prefix):
         app = self.make_interactive_app('hips', 'hippo', 'nonmatching')
-        self.assertEqual(set(app.completenames(prefix)), set(expecteds))
+        self.assertEqual(
+            set(app.completenames(prefix, '', 0, 1)), set(expecteds))
 
     def test_cmd2_completenames(self):
         # cmd2.Cmd define do_help method